Reactions of clay condensates with n-alkanes: comparison between clay volatiles and clay condensates

Long-chain n-alkanes were heated in the presence of clay volatiles or clay condensates, to temperatures up to 250°C in an open and 160°C in a closed system. The product assemblages obtained, which were identified by gas chromatography and gas chromatography-mass spectrometry, resembled each other and those formed on direct contact with the clay minerals. The composition of the assemblages indicates that catalytic cracking occurred. It appears that reactive species, which were previously detected and identified in the volatiles and condensates, act as acid catalysts. Under the mild conditions of the experiments the n-alkanes remained unchanged in the absence of a catalyst and catalysis by clay mineral surfaces had not yet come into play. The persistence of the reactivity of clay volatiles in the condensates implies that fluids derived from clays may catalyse processes that are removed in space and time from the immediate vicinity of the minerals.